Processing parameters of melt mixing (one of the most conventional techniques in polymer processing) play a significant role in the quality and properties of the resulting material, especially when nanoreinforcements are involved. The current study investigates varying processing temperature, rotation speed and elements of the screw extruder, aiming to enhance mechanical properties of polyethylene (PE) nanocomposites by improving dispersion of nanoparticles from a commercial masterbatch in two grades of PE. The study investigates the effect of a common compatibilizer (MAPE) and shearing forces at varying amounts of graphene nanoplatelets (GNPs) in polyethylene. A comparison is made on mechanical properties, morphology, and changes in the microstructure. Results show that increasing amounts of GNPs lead to expected continuous increase of mechanical properties with reference to the base polymer. Addition of MAPE did not result in significant improvement in the performance of the studied systems. Use of stronger shear forces resulted in mostly negative impact on the properties.
The work is performed under joint financial support of the project Smart-WPC funded by the Interreg-Nord framework and region Norrbotten, the project Nano2Day funded by the European Union in the Horizon 2020 programme, and the excellence and innovation area of Smart Machine and Materials (SMM) at LTU. The authors would like to thank students at Luleå University of Technology, Vanessa Meulenberg and Lena Brunnacker (within the course T7009T) for help in performing experiments. Support of engineers Runar Långström and Robert Westerlund at RISE with the manufacturing of the nanocomposites is also highly appreciated.